1. Field of the Invention
The invention described herein relates to methods and apparatus for eliminating intermodulation interference in a wireless communication system.
2. Description of the Related Art
Wireless communication systems depend on electromagnetic waves at various radio frequencies to transmit and receive information. For communication systems such as cellular phones, pagers, and cordless mobile phone, the usable radio frequency spectrum extends from about 300 MHz to 3000 MHz. This spectrum of radio frequencies used for wireless communication is further divided into individual bands wherein each band contains a range of frequencies. Each range of frequencies may be used differently and perform different functions. Furthermore, the radio frequency spectrum is shared by civilian, government, and military users according to International Telecommunications Union (ITU) radio regulations. For example, among these frequency ranges, the one between 806 MHz to 809 MHz is assigned to the National Public Safety Planning Advisory Committee (NPSPAC) to provide public safety mobile services, the one between 817 MHz to 824 MHz is licensed to Nextel Communication Inc. to provide enhanced specialized mobile radio (ESMR) services including voice and data dispatch applications, and the one between 824 MHz to 849 MHz is assigned to various cellular phone service providers to provide commercialized cellular phone services.